Scroll lag like in Safari

[kevinjohncutler]

This project is awesome, thanks for sharing it. I'm finding that (at least on macOS 11.3), there is a significant amount of scroll lag, exactly as seen in Safari (it takes a sec for the page to render). I've been using Firefox and the scrolling experience is perfect - but the occasional crash (always when the notebook is rendering a vispy canvas that is particularly intensive) is not. I can only speculate that Firefox is caching everything in the (admittedly huge) notebook, whereas Safari and JupyterApp are not. I have no idea if this can be changed on the JupyterApp end at all, but thought I might as well flag it for anyone else experiencing the issue.